Friction disc drive



Aug. 24, 1965 w. K. HEINTZ FRICTION DISC DRIVE Filed April 4, 1963 ffl? rcured to a common carrier shaft.

United States Patent O 3,202,003 FRICTIN DISC DRIVE i Walter K. Heintz, Westfield, NJ., assignor to Ford Motor My invention relates generally to friction disc drives, and more par-ticularly, to friction disc drives having ininit'ely variable speed ratio characteristics.

My invention is adapted especially to be used in a disc drive arrangement having power input discs disposed concentrically within power output ring discs, and wherein so-called carrier discs are employed for establishing a driving connection between the power input discs and the power output discs. The carrier discs may be mounted upon carrier structure that may be moved radially with respect to the common axis of the power input discs and the power output discs to establish infinitely vari-able speed ratios.

A 'single pair of power input discs, a single pair of power output discs and a single carrier disc could be employed, but the capacity of the mechanism would be reduced. If -a plurality of carrier discs and several pairs of power input discs and-power output discs are employed, the carrier discs must be capable of accommodating a slight degree of angular tilting or relative misalignment as the carrier is moved from one radial position to another. This is due to the fact that the carrier discs normally are formed with a so-called conical shape with the transverse dimension at the hub portion of the carrier disc being greater than the transverse dimension of the rim portion. For example, if the carrier is moved to a low speed ratio position, the power input discs tend to move toward each other, but the power output discs tend -to move farther apart. The converse is true upon movement of the carrier to a high speed ratio position. Becauseof this misalignment problem, it is common practice to form the carrier discs in two groups that are se- Thus, the carrier discs of one group can move to accommodate corresponding axial movement of the power input discs while the other l that are" obtained during operation of the mechanism vunder reduced torque are in excess of that which is needed.

The improvements of my invention eliminate the foregoing shortcomings. I have provided a means for establishing a driving connection between the driving power input discs and the driven power output discs by means of a carrier disc assembly without the need for grouping the discs ofthe carrier disc assembly in two pairs. I Ahave done this while avoiding the undesirable misalignment problem.

According to another feature of my invention, I have yprovided a means for loading the relatively engageable friction discs hydraulically. The magnitude of the pressure force that may be applied to the contact surfaces of the discs can be varied depending upon the torque transmitting requirements of the mechanism. Thus, the optimum loading of the contact areas is achieved at lall times.

The provision of an improved disc drive mechanism fof 'the type above set forth being an object of my invenice tion, it is a further object of my invention to provide a disc drive having concentric power input and power output discs wherein each of the discs defines its own pressure chamber. Each chamber is adapted to be loaded hydraulically to accommodate the necessary axial shifting movement of the discs due to changes in the radial position of the cooperating carrier disc assembly.

It is a further object of my invention to provide a disc drive of the type above set forth wherein the pressure chambers defined by the power output discs are isolated from the pressure chambers defined by the power input discs so that each may be loaded with a pressure that is sufficient to establish the desired contact forces.

Further objects and features of my invention will become apparent from the following description and from the accompanying drawings wherein:

FIGURE 1 shows an example of a prior art friction drive employing a single pair of power input discs, a single pair of power output discs and a single set of carrier discs;

FIGURE 2 shows a construction similar to that of QFIGURE 1 although a plurality of ring discs, power input discs and carrier discs are provided; and

FIGURE 3 shows my improved construction in cross sectional form.

Referring first to FIGURE l, I have shown in schematic form a conventional prior art construction having a power input shaft 10 and a power output shaft 12. Splined to the power input shaft 1d is -a pair of sun discs 14 and 16. A splined connection between shaft 1i) and discs 14 and 16 will permit axial shifting movement of the discs to occur although relative rotation of these discs with respect to shaft 10 is inhibited. A clamping force can be applied to the discs 14 and 16 by means of a spring 18.

Shaft 10 can be piloted within a pilot opening 20 in shaft 12. This opening 20 is located in the hub of a power output drum 22 that carries ring discs 24 and 26. These discs also are spring loaded into clamping eng-agement, suitable springs 28 being provided for this purpose.

Disposed between the power input discs and the power output discs are carrier discs 30 of conical form. These discs are carried by disc carrier shafts 32. These shafts may be moved radially inwardly or radially outwardly as indicated by the arrows. They are journaled in bearing blocks, one of which is designated by reference character 34.

It lis .apparent that shaft 10 will be capable of driving shaft 12 at a reduced speed ratio. If thecarrier discs 39 are moved radially outwardly, the speed ratio will decrease. Conversely, if the carrier discs are moved radially inwardly, the speed ratio will increase. The springs 18 and 28 establish the neecssary frictional connection between the carrier discs and the driving and driven discs.

The device of FIGURE l, since it employs a single disc, necessarily is of a reduced capacity. To increase its capacity the number of carrier discs can be increased as indicated in FIGURE 2. For purposes of clarity, the parts of the structure of FIGURE 2 that have counterparts in FIGURE l have been indicated by similar reference characters although primed notations have been added. The carrier discs of FIGURE 2, like the carrier discs of FIGURE 1, are conical in form. Thus, as the carrier is moved radially outwardly, the driving discs ldand 16 become misaligned.

In addition to the discs 14 and 16', two other power input discs are provided as indicated at 36 and 38. In

Va similar fashion, power Output discs 4i) and 42 are pro- 'vided in addition to power output discs 24 and 26.

It will be observed from an inspection of FIGURE 2 that as the carrier discs are moved radially outwardly, the power output discs move apart and the power input discs move together. This produces a tilting action ofV the carrier discs which undesirably increases'the degree of friction at the contact surfaces and reduces the torque transmitting capacity of the. unit. Y. Also, .a considerable Referring next to my improved constructionof FIG- URE 3, Ja driving shaft is indicated gene`rally1by'refer- .ence character 44 -and a. driven shaft is. shown .at .46.

YShaft 44 isformed witha reduced diameter externally .splined portion 48 anda shoulder Y501s situated atrthe .Y

jregion of the change in diameter. Disposed adjacent shoulder. 50 is a rst driving disc 52 driving a rim portion 54 of circular dimensions when viewed in cross 15 formed inlshaft-44.Y Thus, uid maybe introduced into section. Y

The hub of disc 52 is internally splined -to establish a .driving connection with the externally' splined shaft poi- .tion 48. y

Disposed adjacent disc .52'is a second driving disc formed in tworparts that are identied separately by reference numerals 56-and 58. Each disc part 56 andk 58 .includes a hub that isinternally splined to the shaft portion 48.V The hub of disc part`56 is disposed` in sealing Iengagement* with the 'hub l50l of disc 52.' Similarly, the

hub of disc part 58 sealingly engages the hubof disc part 56.- l j Anotherjbipartite driving ldiscris disposed Yadj'a'cerit disc part 58. The separate parts of. this other. disc are identiiied by reference characters 60 and 62. Thehub'of disc part 60 sealingly engages thev hub of disc part 58 and the hub of disc part 62 sealingly engages the hub of disc part 60,' f p The hub offa nal driving disc is shown at 64. This disc may be substantially a mirror image of Ydisc 52 It includes an internally splined hub that sealingly engages the disc part 62. Itis formed also with a rim portion 66 of circular crosssection asindicated.

. A clamping nut 6 8 threaded upon Vthe end of shaft 44 maintains -the hubs jof theidriving discs in clamped sealing engagement.; 'An .extension 7'70 vof the-,nut-68 is The right-handvend of shaft 44 is formed vof reduced diameter rand is received withina piloty opening V.'74 in shaft46.f.zThe shaft 144 is journaled withinfthisA opening by meanso'f bushing76. a

' A disc drum is indicated `by'relerence character 78. It ris thre'a'clably connected to the periphery 'of' a circular` 4drive plate 80, suitable dthreaded 'portions 82.gbeingrpro-f ,50 discs is indicated by reference characters. 140142and vided for thisrpurpose. An annular groove 84 .also is r'forined onthe `periphery of yplate 80 and an O-Vring issituated therein to4 establish a fluid seal between thefdrum 7Sandtheplate80.' D 1 1' Drum 78 is formed with an end'freaction shoulder86; It is formed 'also withr internal splines to establish` av 'splined drivingconnection Withla series of'driven discs, rthe rst of which is designated by reference character 88.V

This' 'discA isformedl with lan externally splined hubV and with a rounded inner periphery "90.

" Abipartitedriven discV comprising parts^92and 94 is situated-adjacent driven disc 38. Similarly, a second bipartitev drivenA 'disc/is disposedadjacentl the-rst` driven disc; The parts ofV 'this"sec`ond'disc.areV desi'gnz'tted`l.byl reference characters 96v and 98.y VlA'nal drivendisc 100 Iis `disposed adjacent d iscpart 9S. Each of thediscs and fdisc parts is formed with a rhub* that' is externally splined to establis'ha'driving connection with the internalrspline's of drum 78'.y The adjacent peripheral portionsof the ll '-disc-partsfand the'disc 100 are. disposed in .abutting sealf ing' relationship withV respect to eachv other. f. They are held axially fast bya shoulder 102 formed onftheperiphl ery'y of Yplate 80.V yAs Vthe drum 78 is threadably received over-the' plate 80, shoulder-'102 clamps together the driv" ing discs and the driven disc parts.

- :The .driving disc parts' s6,- ss, 6o and 62 are infine form -of Belleville springs. Discpart 56 `includes a rounded peripheral` portion 104 that isA disposed in juxtaposed relationship with respect to a corresponding peripheral portion 106 formed on adjacent disc part.58.y Situ- Y5 ated between .the peripheral portions 104 and 106 is an annular sealing'ring 108.V The disc parts 56 and 58 and `tlie sealingfri'ng 10S cooperate to deline a pressure cavity that isV designated'by reference character 110. Y

This pressure cavity 110 communicates with the splines on shaft portion 48 through a radial port 112 which lis-formed by means of adjacentrradial grooves in the hubs of disc parts4 56 and '58'. The grooves in turn are adapted 4tojreceivefluid froml a radial passage `114 which in turn' communicates with a central passage 116 the cavity110b`y distributing pressurized fluid to passage 116 through passager114l, through the grooves formed by pthe'splines ofthe shaftY portion 48 .and iinallyvthrough radial passage ,112.

Thediscpa'rts 60 and 62 are formed in a'fashion similar to vtheconstruction of vdisc partsf56 and 58. They cooperate to define a `r pressure cavity V118 and they include a sealing ring120'which lis' disposed between their roundedouter. peripheries The cavity 118 communi- 25. cates withjthe axial passages* formedby'the splines of s shaft part' 48 through .a radialport .122,the latter in turn '.'being formed vby radial grooves in the hubsof disc parts A '-Disc parts92V and 94 arefformed with rounded inner peripheries asindicated yat 124v and 126, respectively. A circular sealing ring`128 is situated between the peripheral lportions .'124'and1'26. The outer margins of the .disc parts 92and94 are grooved to provide a'radial passage ,130 that communicates withv axialf passages formed by ,the splines of drurn'78.,v f

Disc parts 96 andv 98 are nformed in a fashionY similar Vto .the construction off disc partsI 92'y and 94,and they'cooperateV with. a vsealing ring .132 to denea pressure cavity.

y. y f T The pressure cavities deiinedk by thedisc parts'92 and 194 and bythe disc parts` 96 and 98 communicatewith Apassages 1.34 formed in shoulder102. These passages. 134 communicate :also with passages 136 which extend to the '.hub 'of .plate 80. Axially 4extending "passages 138 are formed in Vdriven shaft 46.- .These passages 138 communi- "cate withfthev radially inward extremities of passages 136. Several .series ofcarrier discswith conical profiles are vprovided vfor establishinga driving .connection between Y the driving disc` anda drivenrdisc. One group of carrier .1744. Theyare formed with'splined openingsV inwtheir yrespective'hubs'to facilitate .a driving kconnection-:with jexter'nallyy splinedplanet ydiscsnsupporting Ashafts A1146.

. These f shaftsA 146- -are .journaled .within carrier. disc bearingblocks and:150. Several 4groups-of carrierdiscs l'can beV provided, preferablyfthree in number.Y They vmay be moved radially bymeans .of a suitable mechanical'adjusting ymechanismsuch as 4that ysho'wngin Skuba Patent No. 3,043,150. fThisA radial niotion is indicated in FIG- URE 3 by means ofa doublearrow 152. v s y j f iAs indicated in'V FIGURE 3,the outer peripher'yif disc Y140 is disposedV betweenrthe outer` peripheries of disc 52 C i and .disc part v5.6. i Theouter peiipheralextremity. of the rdisc 140 is disposedbetween the inner vperipheral margin '4 of disc 88 and disc part 92. .V

' When the planet disc assemblies are moved toward the axis of shaft 443,the disc parts 5.6,'- 58; 60 andf62 willtend to become compressed together andthe pressurecavities 110 and 118 will become reduced in volume. At the same time, the disc parts 92, 94, 96 and 98 will move apart thereby increasing the volume of their respective pressure chambers. It will be observed, however, that the planet discs at all times will be radially aligned with the driving discs and the driven discs and the tilting action represented schematically in FIGURE 2 will not take place.

The clamping force 4that is obtained in this drive is somewhat ratio sensitive inherently by reason of the Belleville spring action of the disc parts. For example, the disc parts will provide a greater clamping force when they are compressed axially. The clamping force, however, can be controlled more accurately by introducing the desired fluid pressure into the pressure cavities defined by the disc parts. The pressure distribution to the cavities for the driving disc parts can be controlled separately from the pressure that is distributed to the driven disc parts since separate circuits are provided as previously described.

Having thus described a preferred embodiment of my invention, what I claim and desire to secure by U.S. Letters Patent is:

1. ln a friction disc drive, a first disc comprising two juxtaposed parts, one periphery of each disc part being disposed in sealing relationship with respect to the corresponding periphery of the other disc part, a deformable sealing ring disposed between said one periphery of each of said first discs, said disc parts and said sealing ring cooperating to define in part a pressure chamber, a set of other discs frictionally contacting said one peripheries of said disc parts, said first disc being rotatably mounted for rotation about a first axis, said other discs being rotatably mounted for rotation about a second axis, and means for introducing fluid under pressure to said pressure chamber, and means for holding the inner peripheries of said driving disc parts axially fast whereby said outer peripheries are adapted to exert an axial clamping force upon introduction of pressure into said pressure chambers.

2. In a friction disc drive comprising driving discs and driving discs situated in coaxial relationship, each of said driving discs including juxtaposed parts, the outer peripheries of said disc parts having a deformable sealing ring disposed therebetween, said parts and said sealing ring cooperating to define pressure cavities, a series of intermediate carrier discs disposed in interdigital frictional driving relationship with respect to said driving discs and said driven discs, and means for introducing fluid under pressure to said pressure cavities, and means for holding the inner peripheries of said driving disc parts axially fast whereby said outer peripheries are adapted to shift axially upon introduction of pressure into said pressure cavities as said driving discs are flexed during radial movement of said carrier discs.

3. In a friction disc drive comprising driving discs and driven discs situated in coaxial relationship, each of said driving discs including juxtaposed parts the outer peripheries of said disc parts having a deformable sealing ring disposed therebetween, said parts and said sealing ring cooperating to dene pressure cavities, a series of inter- -mediate carrier discs disposed in interdigital frictional driving relationship with respect to said driving discs and said driven discs, means for introducing fluid under pressure to said pressure cavities, each of said driven discs being comprised in part by adjacent juxtaposed driven disc parts the inner peripheries of said driven disc parts having a deformable sealing ring disposed therebetween, said driven disc parts and said ring also cooperating to define pressure cavities, means for introducing fluid under pressure to said last-mentioned pressure cavities, said carrier discs each being formed with a generally conical shape having a peripheral axial dimension that is greater than the axial dimension of its hub portion, means for holding axially fast the inner peripheries of said driving disc parts and the outer peripheries of said driven disc parts whereby said driving and driven discs are adapted to be flexed upon radial adjustment of said carrier discs.

4. In a friction disc drive mechanism comprising driving discs and driven discs situated in coaxial relationship, each of said driving discs including juxtaposed parts, the outer peripheries of said disc parts having a deformable sealing ring disposed therebetween, said parts and said sealing ring cooperating to define a pressure cavity, a series of intermediate carrier discs disposed in interdigital frictional driving relationship with respect to said driving discs and said driven discs, means for introducing fluid under pressure to said pressure cavities, each of said driven discs being comprised in part by adjacent juxtaposed driven disc parts, the inner peripheries of said driven disc parts having a deformable sealing ring disposed therebetween, said driven disc parts and said sealing ring cooperating to dene a pressure cavity, means for introducing uid under pressure to said last-mentioned pressure cavities, said carrier discs each being formed with a generally conical shape having a peripheral axial dimension that is greater than the axial dimension of its hub portion, and means for holding axially fast the inner peripheries of said driving disc parts and the outer peripheries of said driven disc parts whereby said driving and driven discs are adapted to be flexed upon radial adjustment of said said carrier discs, said carrier discs being movable radially to adjust the speed ratio of said mechanism, the volume of the pressure cavity of said driving discs increasing and the volume of the pressure cavity of said driven discs decreasing as said carrier discs are moved radially outwardly.

5. In a friction disc drive comprising driving discs and driven discs situated in coaxial relationship, said driving discs including juxtaposed parts that cooperate to define pressure cavities, a series of intermediate carrier discs disposed in interdigital frictional driving relationship with respect to said driving discs and said driven discs, means for introducing iiuid under pressure to said pressure cavities, said driven discs being comprised in part by adjacent juxtaposed driven disc parts that cooperate to define therebetween pressure cavities, means for introducing fluid under pressure to said lastmentioned pressure cavities, said carrier discs each being formed with a generally conical shape having a peripheral axial dimension that is greater than the axial dimension of its hub portion, said carrier disc being movable radially to adjust the speed ratio of said mechanism, the volume of the pressure cavity of said driving discs increasing and the volume of the pressure cavity of said driven discs decreasing as said carrier discs are moved radially outwardly, the peripheral portions of said driving discs and said driven discs that engage said carrier discs having received therein an annular sealing ring that cooperates with said disc parts to define their respective pressure cavities.

References Cited by the Examiner UNITED STATES PATENTS DON A. WAITE, Primary Examiner. 

1. IN A FRICTION DISC DRIVE, A FIRST DISC COMPRISING TWO JUXTAPOSED PARTS, ONE PERIPHERY OF EACH DISC PART BEING DISPOSED IN SEALING RELATIONSHIP WITH RESPECT TO THE CORRESPONDING PERIPHERY OF THE OTHER DISC PART A DEFORMABLE SEALING RING DISPOSED BETWEEN SAID ONE PERIPHERY OF EACH OF SAID FIRST DISCS, SAID DISC PARTS AND SAID SEALING RING COOPERATING TO DEFINE IN PART A PRESSURE CHAMBER, A SET OF OTHER DISCS FRICTIONALLY CONTACTING SAID ONE PERIPHERIES OF SAID DISC PARTS, SAID FIRST DISC BEING ROTATABLY MOUNTED FOR ROTATION ABOUT A FIRST AXIS, SAID OTHER DISCS BEING ROTATABLY MOUNTED FOR ROTATION ABOUG A SECOND AXIS, AND MEANS FOR INTRODUCING FLUID UNDER PRESSURE TO SAID PRESSURE CHAMBER, AND MEANS FOR HOLDING THE INNER PERIPHERIES OF SAID DRIVING DISC PARTS AXIALLY FAST WHEREBY SAID OUTER PERIPHERIES ARE ADAPTED TO EXERT AN AXIAL CLAMPING FORCE UPON INTRODUCTION OF PRESSURE INTO SAID PRESSURE CHAMBERS. 